Lock joint seam for pipe



April 21, 1936. A. G. SIEBENLIST LOCK JOINT SEAM FOR PIPE Filed Dec. 10, 1934 2 Sheets-Sheet 1 I N VEN TOR.

A TTORNEY.

April 1, 1936. A. G. SIEBENLIST LOCK JOINT SEAM FOR P IPE 2 Sheets-Sheet 2 Filed Dec. 10, 1934 ATTORNEY.

gPatented Apr. 21, 1936 I 7 2,038,389

UNITED: STATES PATENT OFFICE LOCK JOINT SEAM FORPIPE Anthony G. Siebenli'st, Milwaukee, Wis, assignor to Milcor Steel Company, Milwaukee, Wis., a corporation of Delaware Application December 10, 1934, Serial No. 756,719 3 Claims. (01. 138-74) This invention relates generally to sheet metal 'Figure 6 is a view in longitudinal section taken pipe such as stovepipe or the like and is conon line 66 of Figure 4.- cerned more particularly with a lock joint seam Referring to'the drawings, the numeral I desigi'or such pipe. nates a pipe section which, as usual, is made up 5 The-type, of pipe in which the present invenfrom a rectangular sheet 01 metal of appropriate 5 tion is embodied is designed to be shipped nested gauge and resiliency. Generally speaking, interin suitable packages or cartons and assembled at locking fo ma i n ar form d alon the e s the point 01' seal or use. v oi the pipe section and these interlocking forma- Among the objects of the present invention are tions comprise a female member or resilient to provide a pipe of this character which may be socket 2 and a cooperable male member 3. 10

readily and economically produced, which has its The female member 2 is formed by iolding'one seam members or formations so constituted as to edge of th pip nwa y p itself indicated be susceptible of easy and quick assembly but at 4, thus forming a wall 5- The p pe is f ld which, when assembled, provide a permanent and as at 6 to form an inner wall I. The outer-edge smoke tight seam or joint, one which will not p rtion of thi inner Wall 1 is rned nwar y 15 come apart under forces met with in transportaat 8 to provide a locking. flange 9 spaced slightly tion or use and which, in fact, is so positive and from its wall 1. The bend or told 8 lies inwardly secure, that it cannot be taken apart. otand may be in substantially the same radial Along with these advantagesthe seam forma-- plane 8 the fi st o d be d 4 d t s ca e o tions require but the minimum amount of m tal the mouth or entrance I0 01' the female or socket 0 and present no sharp edges in such manner as to m m r 2 Wi h n the c in f the p n in be liable to injure the person assembling the pipe. such relation to the male member 3 that the male No special skill or tool is required to interflt the m mber may be entered thereinto by m vin the seam members and complete the joint. male and female memberstoward each other in The desirable locking-action is had by a novel a P h el mf r h l y f he Pip section. This 25 interengagement of raw edges so related as to inm v m nt n d n be mp to h entir crease the security of the interlock under the inl n th. f e P pe cti s t n us y but fluence of strains tending to openup the joint and m y e m ed o he m le and female memalso so related and positioned as to bring into e s p e sive y rom one e d o t e p pe to t e play the. strongest characteristics of the metal e making up the edges in resisting the strains and The m m r} is ade p a n ue ll stresses placed thereon. When the pipe is aswhich is ofiset from the main wall of the pipe by sembled a smooth joint flush with the exterior an angled 0r slop P01171011 At pa wall of the pipe is had. I tervals along the tongue ll incisions l3 are made Other objects and advantages reside in certai therein. These incisions or slits are preferably 35 novel features of the construction, arrangement Curved el'cllete form and p nt a Crescentand-combination of parts, which will be hereinlike appearance and similarly shaped edge It afte more fully described and particularly The metal oi the tongue adjacent each incision l 3 pointed out in t appended claims, reference is displaced or pressed inwardly as at l5 so as to 40 mg had to accompanying drawings forming locate the edges l4 inwardly of the inner wall 01' 40 a, part of this specification, and in which: gg g g ll and so as w W locking cups Figure 1 is a iragmentary view'in elevation I with this construction, when the tongue H of owing pipe Se won having joint embodsmg the male member 3 is moved into the mouth I0 the present invention, the joint being shown or the pocket m the edges snap under the 45 ope A Figure 2 is a sectional view taken on line 2! 2 53 35 2 5 gagi g if 53%,: of Figure a gether. As each tab I6 is inoved into place it Figure 3 is a View similar to Figure 2 but Show comes into effective locking action and cannot in! the seam membersintermked and h be accidentally disengaged. This facilitates as- 50 clo d: sembly in that the possibility of the pipe spring- Figure 4 is a fragmentary view on an enlarg d ing open after it has been locked part way along scale, partly in elevation and partly in section; its length is avoided.- In moving in through the Figure 5 is a view similar to Figure 3 of a modi mouth of the pocket each tab or clip l6 flexes or 55 fled form of the invention; and displaces the inner wall I of the pocket suillcientli 56 parts and the pressure exerted on the sloping portion of the male member by the first fold or bend 4 causes the edge 14 to snap and hook under the flange 9 and the parts are permanently locked together.

-The tongue II and pocket ID are so dimensioned and the tabs l6 and locking flange 9 are so related that the parts are not only held against pulling apart but against longitudinal shifting. This is entirely true of the structure just described which is a preferable construction but if desired a further frictional effect may be set up between the members of the seam or joint by outwardly displacing portions 20 of the tongue in between thelocking tabs l6 as illustrated in Figures 4 and 5. These outwardly displaced portions 20 do not have a set up additional frictional engagement between the members of the joint.

It will be appreciated that an important feature of the invention resides in the novel and advantageous character of the lock set up between the edge of the locking flange and the edge surfaces presented to said locking flange edge by the ends of the incisions from which the locking tabs are displaced. Another factor in obtaining a thoroughly effective and reliable lock is the engagement of the locking tabs with the undersurface of the locking flange. By having the offset or sloping portion l2 disposed to be pressed against by the first bend in the closed position of the seam, proper interlock is assured and a better joint is had. Then again, the offset portion l2 provides for a substantially smooth, flush and unbroken joint. It should ,be noted also that in the assembly the incisions are entirely contained in and enclosed by the imperforate walls of the female member.

and that various changes in the size, shape and arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subjoined claims.

-.sions, the material of locking action but merely The invention claimed is:

1. A pipe section having one edge folded inwardly upon itself and then refolded to provide spaced walls enclosing a pocket, the inner wall having its edge flange spaced from the walls of the'pocket, said first and last folds being disposed in substantially radial alignment and defining the mouth of the pocket, the other edge of the pipe being offset folded inwardly and providing a inwardly to provide a tongue, said tongue being 10 insertable in said pocket and having spaced incithe' tongue adjacent said incisions being depressed inwardly so that when said tongue is inserted in said socket the stiff edges of said displaced portions will engage under 5 the flange to lock together.

2. A pipe section having one edge folded inwardly upon itself and then refolded to provide spaced having its edge folded inwardly and providing a the edges of the pipe section locking flange spaced from the walls of the pocket, the other edge of the pipe being offset inwardly to provide a tongue, there being a sloping connecting portion main portion of the pipe, said sloping connecting portion being engaged and pressed inwardly by said first-named fold when said tongue is inserted in said pocketand rigid locking members walls enclosing a pocket, the inner wall between said tongue and the on said tongue engageable with said locking 3 flange.

3. A pipe section having one edge folded inwardly upon itself and then refolded to provide a pocket defined by spaced walls, said nating within the pocket in spaced other edge being oifset inwardly to provide a tongue insertable within the pocket, said tongue the edge within the pocket when the tongue is inserted therein, said tongue being connected to the pipe section by an inclined portion engageable with the first mentioned fold when the tongue edge termin relation to the walls thereof, said pipe section adjacent to .being provided with inclined lugs engageable with 40 is inserted within the pocket, the connecting portion and the lugs being oppositely inclined whereby to press the tongue into firm engagement with the walls of the pocket.

ANTHONY G. SIEBENLIST; 

